/Engine/Plugins/Developer/Concert/ConcertMain/Source/ConcertTransport/Public/ConcertTransportMessages.h
Special event message base struct that is also caught by the endpoint to discover remote endpoint before passing it to handlers
[USTRUCT](Programming/UnrealArchitecture/Reference/Structs)() struct FConcertEndpointDiscoveryEvent : public [FConcertEventData](API\Plugins\ConcertTransport\FConcertEventData)
EConcertMessage...
ConcertProtocolVersion
Holds the concert messages protocol version, default initialize to `BeforeVersioning_ to handle message sent from older protocol.